Narrative:

During the climb a sudden severe left roll occurred, the captain (PF) stopped the left roll requiring more than 50% aileron deflection to maintain wings level. Full aileron trim was not enough to relieve control pressures. We checked flaps up indications in the cockpit and visually which confirmed flaps up. We determined we had positive roll control, although reduced roll capacity to the right. We requested vectors back to fat at which time ATC asked if we were declaring an emergency. We responded negative. ATC was advised of a mechanical difficulty. Priority handling was not requested or given. We accepted a visual approach clearance to runway 11L fat and made a normal approach and landing. Upon inspection at the gate a large inspection panel immediately forward of the left aileron on the upper surface was observed to be loose and determined to be the cause of the roll. Supplemental information from acn 101893: maintenance inspected aircraft and found all six securing screws missing from left-hand most outboard wing trailing edge panel. Subsequent investigation has shown aircraft had received a B check two days prior in which this particular panel was opened, along with several others, in order to gain access for completion of required maintenance tasks. Further investigation shows several individuals were involved in the close-up of the aircraft at completion of the check but no one persons assumes responsibility or full knowledge of this one particular panel. However, there is a signature of a supervisor who specifically signed stating, 'all panels were secured.' it has been concluded that the fasteners were in place but not fully secured by nature of the aircraft operating the two days without incident. If they were not installed, then by nature of the panels design and purpose, it would have had a problem from the first flight after completion of the check. Because of not being able to specifically determine any one person's involvement, the air carrier is taking several actions. One, initiate a 'open-close' sign-off task card specifically designed around the respective check. Two, paint the adjacent area around the closure screws heads to allow visual contrast of the lastly, corrective action against the sing-off supervisor for not fully assuring job completion.

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Original NASA ASRS Text

Title: ACR LTT EXPERIENCED SEVERE ROLL DURING CLIMB. RETURN AND LAND. SUBSEQUENT INSPECTION REVEALED IMPROPERLY INSTALLED WING PANEL.

Narrative: DURING THE CLB A SUDDEN SEVERE LEFT ROLL OCCURRED, THE CAPT (PF) STOPPED THE LEFT ROLL REQUIRING MORE THAN 50% AILERON DEFLECTION TO MAINTAIN WINGS LEVEL. FULL AILERON TRIM WAS NOT ENOUGH TO RELIEVE CONTROL PRESSURES. WE CHECKED FLAPS UP INDICATIONS IN THE COCKPIT AND VISUALLY WHICH CONFIRMED FLAPS UP. WE DETERMINED WE HAD POSITIVE ROLL CONTROL, ALTHOUGH REDUCED ROLL CAPACITY TO THE RIGHT. WE REQUESTED VECTORS BACK TO FAT AT WHICH TIME ATC ASKED IF WE WERE DECLARING AN EMER. WE RESPONDED NEGATIVE. ATC WAS ADVISED OF A MECHANICAL DIFFICULTY. PRIORITY HANDLING WAS NOT REQUESTED OR GIVEN. WE ACCEPTED A VISUAL APCH CLRNC TO RWY 11L FAT AND MADE A NORMAL APCH AND LANDING. UPON INSPECTION AT THE GATE A LARGE INSPECTION PANEL IMMEDIATELY FORWARD OF THE LEFT AILERON ON THE UPPER SURFACE WAS OBSERVED TO BE LOOSE AND DETERMINED TO BE THE CAUSE OF THE ROLL. SUPPLEMENTAL INFORMATION FROM ACN 101893: MAINT INSPECTED ACFT AND FOUND ALL SIX SECURING SCREWS MISSING FROM LEFT-HAND MOST OUTBOARD WING TRAILING EDGE PANEL. SUBSEQUENT INVESTIGATION HAS SHOWN ACFT HAD RECEIVED A B CHECK TWO DAYS PRIOR IN WHICH THIS PARTICULAR PANEL WAS OPENED, ALONG WITH SEVERAL OTHERS, IN ORDER TO GAIN ACCESS FOR COMPLETION OF REQUIRED MAINT TASKS. FURTHER INVESTIGATION SHOWS SEVERAL INDIVIDUALS WERE INVOLVED IN THE CLOSE-UP OF THE ACFT AT COMPLETION OF THE CHECK BUT NO ONE PERSONS ASSUMES RESPONSIBILITY OR FULL KNOWLEDGE OF THIS ONE PARTICULAR PANEL. HOWEVER, THERE IS A SIGNATURE OF A SUPVR WHO SPECIFICALLY SIGNED STATING, 'ALL PANELS WERE SECURED.' IT HAS BEEN CONCLUDED THAT THE FASTENERS WERE IN PLACE BUT NOT FULLY SECURED BY NATURE OF THE ACFT OPERATING THE TWO DAYS WITHOUT INCIDENT. IF THEY WERE NOT INSTALLED, THEN BY NATURE OF THE PANELS DESIGN AND PURPOSE, IT WOULD HAVE HAD A PROBLEM FROM THE FIRST FLT AFTER COMPLETION OF THE CHECK. BECAUSE OF NOT BEING ABLE TO SPECIFICALLY DETERMINE ANY ONE PERSON'S INVOLVEMENT, THE AIR CARRIER IS TAKING SEVERAL ACTIONS. ONE, INITIATE A 'OPEN-CLOSE' SIGN-OFF TASK CARD SPECIFICALLY DESIGNED AROUND THE RESPECTIVE CHECK. TWO, PAINT THE ADJACENT AREA AROUND THE CLOSURE SCREWS HEADS TO ALLOW VISUAL CONTRAST OF THE LASTLY, CORRECTIVE ACTION AGAINST THE SING-OFF SUPVR FOR NOT FULLY ASSURING JOB COMPLETION.

Data retrieved from NASA's ASRS site as of August 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.